Steam curls like soft ghosts in the evening air, each tendril catching the gold of paper lanterns strung between weathered wooden eaves. The narrow street is empty, save for the gurgle of water flowing from bamboo spouts into stone basins. The scent of plum blossoms drifting from a courtyard somewhere beyond the walls.

You walk beside Shiro. The mission is over—no Sentinels, no chaos, no shouting—yet he’s still simmering. Not the nuclear flare that’s earned him his name, but the slow, dangerous burn you’ve learned to recognize in the set of his shoulders and the steel of his jaw.

Shiro doesn’t do “relaxed.” Even in this quiet hot spring town, his eyes scan every shadow, his back never fully to a wall. His pride bristles against the simple fact of being here on Xavier’s orders, partnered with you because, apparently, you’re “the only one who can calm him down.” You never said yes to that label, but the team has noticed the way his temper shifts when you speak.

“Yoshida,” you say softly, letting the syllables rest in the air like a warm cloth over a fever. His gaze flicks toward you, sharp as flint, before easing a fraction.

“You are too casual,” he mutters, the edge of embarrassment buried under the gravel of his tone. “This is not… a holiday.”

The truth is, you’d noticed the onsen earlier—the steam rising from the rock pools beyond the inn’s garden, the glow of lanterns on water. You’d noticed the way his tense hands had curled just a little when the innkeeper offered private baths to “rest the spirit.” Shiro may breathe fire, but he’s terrible at hiding longing when he’s exhausted.

You mean well when you nudge him toward the idea, teasing lightly.

“Even warriors need to soak now and then.”

He stops walking, and you can almost hear the gears grinding in his head. His glare isn’t sharp enough to cut; it’s more conflicted. That fire in his chest wants to resist, but the weariness in his eyes is betraying him. He looks at the lantern-lit path leading to the bathhouse as though it’s a trap.

“I will not…” he starts, then falters, his gaze skimming away. “This is… inappropriate.”

You almost laugh, but the moment’s too fragile. Instead, you step closer, lowering your voice so the words feel like they belong only to the steam and cedar-scented dark.

The line pulls a twitch from his lips—could be annoyance, could be something softer. He exhales, and the steam swallows his breath like it belongs here.

When you guide him forward, his stride stiffens again, but he doesn’t pull away. The hot spring’s water mirrors the lanterns, rippling gold and shadow. When you shrug off your jacket to hang it on a peg, you can feel the weight of his gaze before he pointedly looks away.

“You truly have no sense of formality.”